Screw-propeller.



' PAT-ENTBD MAR. 20,1906

No. 815,740.I

www w 1B.' K. BURNS. SCREW PROPHLLBR.'

AEPLIOATIQN FILED DEU. 8. 1904.

1 UNITEDSTATES PATENT, oFF-Iony, unmask. PURVIS. for MANCHESTER. Ico-WA.y 'Y Y l vs'CREwi-FRoiiLLIER.Vv l

- Specification of Letters-Patent.v

raten/Gea' Maren 2o'. 1906.

Appnoanon sied Decembe 8,1904. segrinnazsaoaa. Y

To @ZZ whom t may concern,.- 4

v Be it known that I,.ELMER K. PURvIs, a

citizen of the United States, residing at Manchester, in the county of Delaware and State of Iowa, have invented certain new and useful Improvements in Screw-Propellers and I do declare the followin to be a full, clear, and exact description of the invention, such as will enable'others skilled in the art to which 1t appertains to make and use the same'.

My invention `relates to improvements in screw-propellers for ships and in means for` structed and mounted in accordance with my'invention. Fig. 2 is a vertical longitudinal ysectional view through the same. Fig. 3 is avertical transverse sectional view taken on the line 3 3 in Fig. 2. Fig. 4 is a detail transverse sectional view through thescrewpropeller on line 4 4 of Fig. 2, and Fig. 5 is a detail horizontal sectional view taken on the line 5 5 in Fig. 2.

Referring tothe drawin s by numeral, 1

denotes the lower portion o the body or hull.

of a ship or other vessel which has its keel dif vided into two parts 2 and 25L bya longitudinally-extending channel formed in the bottom of the hull. This channel 3, which is open at its bottom and ends, extends throu hout the entirelen th of the ship, so that t e water may pass freely through the` same. Mounted centrally in said channel is a longitudinally# disposed shaft 4, which is journaled in suitable bearings provided in bracket-arms 5', which project from the to and sides of said channel. This shaft is preferably composed of a series of steel tubes 5, which are connected by solid crank portions 6 and which have solid portions 7 in their outer ends for the pur ose of mounting them in the bearings upon t e arms or brackets 5. Upon said tubular sections 5 are secured cylindrical protective ca'sings 8 vthe foremost one of which has its forward end ta- The object of my invention is to improve ypered, vas atr 9.v These lcasings are watertight and are preferably secured by means of radially-extendingv arms or brackets 10, ask

seen in Fig. 4 of the drawings. Upon the cylindrical ca sings v8 are secured spiral screwblades 11, which form a pro eller which revolves in the channel 3. T e spiral blades 11 are vpreferably formed with bent or molded flanges 12, which are secured to the casings 8 by rivets or the like, as seen in Fig. 4

of the drawings. 6 of the crank-shaft 4 is disposed between consists of two cranks. These crank-sec,- tions 6 are disposed directly beneath or 1n line with vertically-extending wells 13, which are substantially elli tical in crosssection, as seen in Fig. 5, wit their forward edge tapered or pointed to cause the same to Each of the crank-sections j two of the'section-casings 8 and, as shown.

cut the vwater passingthrough the channel 3. y

The drivingv connections for operating the shaft extend through these wells or manholes 13, and in order to protect the cranks 6 I provide a casing 14, which has a water tight connection, as shown at 15,V with the ends of the adjacent cylindrical casingsS..

By reason -of these casings 14 water is excluded from the wells 13, as -will be seen upon reference to Fig. 2 of the drawings.

In order to steer the ship, I mount 1n the usual manner at the rear end of each of the keel-sections 2 and 2a rudders 15, which may be operated in any .desired manner. Between these rudders and the ends of the keelsections 2 and 2al are mounted the usual form of screw-propellers 16, which may be used in conjunction with the propeller in the channel 3 lor which may be used only when the latter is rendered inoperative from any cause whatever.

The operation and advantages of my inventionvrwill be readily understood-from the foregoing description, taken in connection with the accompanying drawings. A ship vequipped with this propelling mechanism IOO may be driven at a higher rate of speed than when only the stern propellers are employed, and owing screw-propellerin the channel 3 of the hull of the ship and guarded.

Various changes in the form, proportion,

and the minor details of construction may be resorted to without departing from the principle or sacrificing any of the advantages of this invention.

to the mounting of the spiral said propeller will be Well protected l IIO ar casings on said shaft, separated bottom of the vessel, and casings at the bottoms of the wells, communicating therewith, receiving the opposing ends of the tubular shaft-casings and incasing the cranks.

In testimony whereof I have hereunto set my hand in presence of two subscribing Witnesses.

ELMER K. PURVIS.

Witnesses:

E. B. STILEs, D. C. SQUIRns. 

